The Celtic cross (aka "high cross," or "sun cross") is a familiar, and iconic motif that is associated with Celtic Christianity, although its origins are pre-Christian, dating back to the Bronze Age in the 3rd millennium BC. As a "sun cross," the Celtic cross represents both the Solstices and equinoxes. Other interpretations say that the Celtic cross symbolizes the the four elements of air, earth, fire, and water, or perhaps the four quarters of the earth.

The best known motif in Celtic art and jewelry is the "Celtic knot," with its geometric, interlacing spiral pattern which is similar to that of the ancient Norse culture. The repetitive interlocking pattern is said to represent the bond of friendship, love, unity and marriage (tying the knot), or it could represent the interconnectedness of all living things. Within the seemingly consistent patterns their are several variations that include circles, crosses, spirals, waves, and trinity motifs. The "Trinity knot," or "Triquetras" is said to represent the Holy Trinity, while the Celtic spiral, or "spiral of life" is said to represent the never-ending seasons of the year, and the never-ending cycle of life, death and rebirth.

Although the ancient tradition of glyptic carving remained in practice during the Middle Ages, mainly carried on by Monks, it was believed that recycled glyptic gems from antiquity were the work of nature.